I'm not sure about "cultish", but diehard yes.

Most Republicans stuck out with Nixon to the end. In August 1974, a week before his resignation, a Gallup poll found 57% of Americans supported impeaching and removing Nixon, while 31% opposed. Among Republicans, 59% said they do not think Nixon should be impeached and removed from office while 31% thought that he should. Despite plummeting approval ratings and economic problems on top of the scandal, around a third of the country stuck with the president through the entire Watergate scandal.